CHICAGO (AP) - A winter storm pounding the Midwest caused at least two deaths Friday, authorities said, while closing schools and forcing the cancellation of hundreds of flights.

Snow-related crashed snarled highways across southern Michigan, with one person killed when a semitrailer struck the rear of a car stopped in traffic on U.S. 23 near Flint, police said.

A Michigan State Police trooper was hospitalized after a pickup truck lost control and slammed into his stopped squad on Interstate 94 northeast of Detroit. A pileup on the same highway just east of Kalamazoo in southwestern Michigan of collected 38 vehicle including 16 semitrailers in eastbound lanes Friday afternoon, causing only minor injuries.

In Naperville, Illinois, just west of Chicago, a man in his 60s died after suffering a heart attack while shoveling snow Friday morning, Edward Hospital spokesman Keith Hartenberger told the Chicago Tribune.

The National Weather Service reported 10 inches (25) of snow on the ground Friday afternoon in suburban Chicago and 11 inches (28 centimeters) near South Bend, Indiana. Chicago was forecast to receive as much as 14 inches (35 centimeters) of snow with Detroit expecting up to 9 inches (23 centimeters).

Chicago Mayor Rahm Emanuel said the city was gearing up for three more rounds of snow through the weekend.

"The good news is we're tried and tested here," he said. "We're up to it."

More than 1,000 flights were canceled at Chicago's O'Hare International Airport and more than 300 were canceled at Midway, the Chicago Department of Aviation reported Friday afternoon. More than 260 flights were canceled at Detroit Metropolitan Airport in Romulus, Michigan.

Hank Stawasz was out shoveling his driveway by hand, clearing a path for the retiree to exit his home in the Detroit suburb of Livonia.

"It's part of living in Michigan," a smiling Stawasz said from underneath his Detroit Red Wings winter hat. "I saw the plows come by, so I figured I'd get a jump on it so I wouldn't have to shovel it when it's 4 feet high."

Thousands of children got a rare snow day off school after school districts in Chicago, Detroit and Milwaukee canceled classes. Schools across Nebraska and Iowa also closed or delayed the start of classes.

It made for a great day for kids to go sledding, make snow angels and play with pets outside instead of reading, writing and arithmetic. Angela Lekkas took her children sledding in Chicago's Lincoln Park neighborhood.

"The kids couldn't wait to get out today," she said. "This is the first true snowfall of the season."

The Indiana Department of Transportation resorted to sending teams of as many as four plows simultaneously to clear some highways. Chicago Department of Streets and Sanitation Commissioner John Tully said 300 salt-spreading plows hit the streets late Thursday and would continue their work through the weekend.

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